Many processes such as the mining of copper and nickel ore, produce molecule-size bits that are wanted such as dissolved bits of copper or nickel, and also produce undissolved bits or particles of material such as liquid hydrocarbons. Liquid organics (compounds such as hydrocarbons that contain carbon) can be removed from a stream by introducing gas bubbles, which are usually air bubbles, into the liquid stream. In a separation chamber, gas bubbles in a predetermined size range, such as 60 μm to 100 μm (2.4 to 4 thousandths inch) cling to the unwanted organic undissolved particles and allow them to be separated from wanted dissolved bits. The bubbles keep the organic particles that flow into a separation chamber, from flowing into a media bed from which almost all remaining contaminants including organic particles, are removed. Instead, the organic particles with gas bubbles in the predetermined size range clinging to them, can be removed from the middle of the separation chamber. This prevents the media bed from rapidly becoming clogged with organic bits, and therefore avoids the need to often clean the media bed.
Gas bubbles, which are herein sometimes referred to as air bubbles, can be produced by flowing pressured air through an air diffuser (“bubble device”) into a pressured liquid stream. The diffuser has one or more tiny holes that emit bubbles into the liquid stream. If the bubbles that enter the separation chamber are too large, the bubbles rapidly float to the top of the separation chamber without clinging to organic particles, and are removed without doing any work. If the bubbles are too small, they rapidly move into the media bed and tend to clog the media bed. Only those bubbles of a predetermined size range such as 60 μm to 100 μm cling to the unwanted particles, or bits, and remain near the middle of the separation chamber from which they are removed. An important problem in the separation of organic particles from wanted bits is the control of bubble size, so as to maintain a large proportion of bubbles in the predetermined size range that effectively remove organic undissolved particles from a separation chamber.